Improvement in printing-presses



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c. B. cTTnELL,

` PRINTING-PRESS. No.17iZ,974. Patented Feb.1,1a7.e.

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C. B. COTTRELL.

v.'IFRINTINW3-PRESS. I No.172,974. Patented Feb.1, 1876.

UNITED STATES PATENT @Ferca GALVER'I B, COTTRELL, OFA WESTERLY, RHODEISLAND.

IMPROVEMENT IN lPRINTING-PRESSES.

Specification forming part of Letters Patent No. 172,974, dated February1, 1876; application filed November 27, 1875.

To all whom it may concern Be it known that I, GALvERT B. Go'r'rRELL, ofWesterly, Washington county, in the'State- 'ot Rhode Island', haveinvented certain new and useful Improvements in Printing-Presses; and Ido hereby declare that thefollowing'isl a full and exact descriptionthereof, reference being had to the accompanying drawings, andI to theletters of reference marked thereon.

In drum-cylinder presses as heretofore con.

` structed there is a great deal of backlash in the gearing, resultingfrom thetendency of the drum or impression-cylinder to maintain auniform and greater velocity than the bed is permitted to travel with atand near each end of the stroke of the latter;l and this lbacklash notonly induces to greater-strain and wear and tear of the machine, butrenders the Work imperfect. In cut-Work the imperfecw tion is mostdamaging, the overlays being permitted tostrike over. l

1t will be obvious to those familiarwith the construction and operationof printing-presses that the retardation of the bed (by any of the usualappliances employed to check the velocity and take upY the momentum) atthe end of each stroke of the hitter tends to shift the working sides ofthe teeth of the gearing, and thus occasions more or less strain vand agreat amount of backlash in the gears, which must necessarily induce toconsidera-ble jar and shock, and permit considerable striking over,

all of which is most destructive of the machine and detrimental toperfection of Work.

I propose to overcome all this striking over and imperfection of' work,as Well as the evil consequences to the mechanism of the principle ofconstruction heretofore employed in such presses, by the adopt-ionin,"or use in connec` tion with, such machines of some means for re-ktarding the velocity of the drum or impressioncylinder at the same timethat, and about to the same extent as, the bed is retarded, (at

each end of its stroke,) andthns harmonizing the velocity of the drum4to theirregular velocity of the bed, and keep the gears working alwayson the same sides of the teeth; and to this end and object my inventionconsists ini the use, in combination with the drum, of a means forchecking or retarding its velocity at the right times and to the properextent to make it run with about the same variable velocity as the bed,and thus avoid all backlash and any strain or jar in the working of themachine, and to keep the vgears workingfalways on one side ot' thetooth. i In carrying out this `principle of construction 'it has beendeemed most advisable to so devise the machine that the device foreffecti ing theretardation of the drum shall not be brought intooperation or effect when-the machine is not running'at its usualiworkingvelocity, as then the turning of they drum by hand-power, asis oftennecessary, will not be rendered any more difficult than heretofore.

To accomplish this end is a furthervobject of my invention, whichfurther consists 1n coinbining the drum-retarding device or mechanismwith the governor, or some ruiming part of the machine, in sach famanner that said Adevice or mechanism will be set and held in anoperative condition only when the machine.

has the motive power applied or is running at its usual workingvelocity. My invention further consists. in certaivhereiHatter-described improvements in the delivery-mechanism of thepress. Y l

Ioenable those skilled in the art to make and use my invention, I willproceed to more fully describe the construction and operation of aprinting-press involving .my several iinprovements, referring by lettersto the accompanying drawings forming part of this specification, and inwhich- Figure 1 is a side elevation; Fig. 2, a back view; andFig. 3,avertical longitudinal sec- B the proper motions, and whichkalso,'t'hrough the medium of a pinion, I, intermediate gear. J, andgear-wheel- K, impartsto the drum C the necessary rotatory motion. Onthe main shaft E is a gear, L, that engages with an in` termediate gear,M, which drives the spur-pinion N of the governor O. The griper-wheelsP, for taking the printed sheet away from the drum', are arranged on ashaft, Q, mounted in the upper part of the main frame, as shown, and theiiy R, for delivering the sheets, is arranged, as seen, so as to takethe sheets as they pass out between the wheels P and rollers S.

The liy is operated in any usual manner, and the drum C is provided withthe usual griper-tingers, for carrying the sheet round while receivingthe impression.

The griper wheels P make each three revolutions to one turn ot' the drumC 5 but the cated with reference to the circumference of the drum andthe throw of the bed B that they will come successively into contactwith a brake-block, c2, justabout at the times the bed is being checkedup and reversing its `direction of motion, (at each stroke ofthe bed,)and this brake-block c2 is mounted or formed on the upper end of a bar,d2, which is jointed to another bar, e2, forming a sort of knucklejoint,as illustrated. Extending from this joint is a pitman or rod, f2, thatis connected to the governor, so that when the press is running at itsusual speed the brake-block will be drawn up to the position shown atFig. 3 in full lines, causing the projecting portions a2 b2 of the drumto come into frictional contact with said brake just about the times thebed is being checked up, and so that when the press is not running fullspeed, the said brakeblocks will drop down into disuse, as shown i bythe dotted lines at Fig. 2.

It will be understood that by the means shown and just described thevelocity of the drum C is checked up at the sa me time that the throw ofthe bed is checked, (ateach end of the strolie,) and that, therefore,the irregular speed of the bed is made to harmonize with asimilar'irregular velocity of the drum, and' that thus all backlash, andthe consequent striking over, and all strain, concussion, and wear andtear on the machine, which would otherwise result from the naturaltendency of the rotatory drum to keep traveling fast while the bed isslowed up suddenly, are overcomeV or avoided; and it will be seen thatby combining the brake mechanism with the govsuch a manner that the saidmechanism will be automatically thrown into use or disuse, as themachine is either run by the usual motive power, or is only put inmotion by hand,the unnecessary hinderance to the turning ot' the drum byhand, which would occur were the brake device arranged to always takeeffect, is avoided.

The general operation of the main parts of the press will, otl course,be understood without particular explanations here.

It will be understood that, so far as the first part of my invention isconcerned, any suitable mechanical appliance for checking up the drum,or taking up some of its momentum at the time the bed is (necessarily)being checked, so as to keep the teethvot' the driving-gears alwaysworking on the same side, and so prevent all backlash, strain, and jar,will answer, and that this part of' my invention is not limited by theparticular devices shown, nor restricted to the described mode ofcarrying it out, in which the bringing into use of the drum-checkingdevice is eiectedautomatically, and only when the press has the usualmotive power applied.

O1' course one part or feature of my invention Vmay be used with more orless advantage without the other features; and it will be understoodthat, in regard to the tirst part of my invention, the retardation orretarding of the cylinder is most import-aut at such times as thepriutingoperation is being performed.

. Having so fully explained the construction and operation ot' a machineembracing my several improvements in the form I have so far practicedthat any one skilled in the art can make and use printing-pressesinvolving my invention, `what I claim as new, and `desire to secure byLetters Patent, isy 1. In combination with the druln or impressioncylinder, means for intermittently checking the speed of said cylinderor retarding its velocity', substantially as and for the purposesdescribed.

2. The combination of a brake device or other suitable means forintermittently checking or retarding the velocity of the rotatory drumwith the governor, or some other movement ot' the machine, in' suchmanner that the said drum-checking device will be brought into anoperative condition only when the ma'- chine is running at its full orworking-speed, as hereinbet'ore set forth.

In testimony whereof I have hereunto set my hand and seal this 18th dayof November, 1875.

OALVERT B. COTTRELL. [L. s,] In presence of- J N. MGINTIRE,` JACOBFELBEL".

